Standard hydraulic drilling machines are familiar in existing technology, but never mounted on mini-diggers.
This is the type of drilling machine described by U.S. Pat. No. 5,810,101 with a drilling machine that has a metal chassis, drilling resources, a rotary motor used when drilling, a hydraulic circuit and a electrical circuit. The chassis is secured by its centre to the arm of the digger. The drilling rods are rods with a helical borer and therefore cannot be extended. In this type of drilling machine, drilling is therefore limited to the length of the drilling rod. This drilling machine is intended to be used only with conventional diggers of normal size and not with mini-diggers.
Such drilling machines have several drawbacks. In fact, such drilling machines are not easy to handle. This is due to the fact that they are mounted on excavation chassis or on tracks.
This handling difficulty leads to the digging of trenches that are often wide and deep, this being necessary for the execution of the works, but which disrupt the life of a district or interfere with the traffic.
Such machines cannot be used in small spaces such as alongside safety railings, pavements or embankments, for example.
U.S. Pat. No. 6,179,068 proposes a drilling machine whose size is adaptable by virtue of a portion which can be removed to allow access to confined and small spaces. But as in the previous case, the rod cannot be extended.